In early March, the aircraft carrier USS Carl Vinson and its escort made a port call to Da Nang in Vietnam. It was the first visit of a U.S. aircraft carrier to Vietnam since the end of the Vietnam War more than 40 years earlier. At the welcome ceremony, U.S. 7th Fleet commander Vice Admiral Philip Sawyer told the audience he hoped the visit would promote a relationship between Vietnam and the United States, and provide a foundation to improve ties in the future. Sawyer also said he would “greatly look forward” to bringing a U.S. submarine to Vietnam someday.

The visit of the Carl Vinson was part of a growing trend of foreign naval vessels that have visited Vietnamese ports in recent years. In June 2017, the guided-missile destroyer USS John S. McCain conducted a “routine technical stop” in Cam Ranh Port, Vietnam. Other naval vessels including Arleigh Burke-class destroyers, joined the Carl Vinson in March.

In addition to port visits, U.S. Navy destroyers have conducted several highly publicized freedom of navigation operations (FONOPs) around Chinese-held features in the South China Sea, challenging territorial sea claims deemed excessive by the United States. The pace of these FONOPs has increased year on year; while just one FONOP took place in 2015, the administration of former president Barack Obama authorized three FONOPs in 2016. In May 2017, the Trump administration accelerated the tempo for FONOPs in the South China Sea; the U.S. Navy officially carried out four separate FONOPs May to October last year. Two have already taken place in the first three months of 2018.

But U.S. navy vessels are not the only foreign ones active in the region. Many Japanese naval ships have called on Vietnamese ports recently. Significantly, the helicopter destroyer JS Izumo (DDH-183) conducted its first overseas voyage in 2017, when it visited Vietnam. Japan’s Maritime Self Defense Force (JMSDF) is rumored to have plans for converting the Izumo class, currently comprising the JMSDF’s two largest warships, into true aircraft carriers capable of supporting aircraft like the F-35 Lightning. In this light, the first overseas trip of the Izumo could be just one piece of an increased international presence by the JMSDF under Prime Minister Shinzo Abe—an increased presence that would be planned to counter Chinese influence.

Before the Izumo’s port call, the French came around as well. The French Navy amphibious assault ship Mistral and frigate Courbet visited Vietnam in April 2017. Australian and Indian warships, too, made port calls in Vietnam in 2017. Australia sent the HMAS Ballarat, an Anzac-class guided missile frigate, for a five-day visit to the central city of Da Nang. In September, the Indian Navy’s stealth frigate INS Satpura (F48) and the anti-submarine warfare corvette INS Kadmatt (P29) visited Hai Phong.

The United Kingdom may join the party by sending warships to Vietnam, too. During a two-day visit to Sydney and Canberra, The Australian quoted UK defense secretary Gavin Williamson as saying that the HMS Sutherland, an anti-submarine frigate, would sail through the South China Sea to assert freedom of navigation rights sometime in the coming months . In June 2017, The Guardian also reported UK foreign secretary Boris Johnson as having committed the country’s two brand-new aircraft carriers to freedom of navigation exercises in South China Sea.

It is worth highlighting that these port calls were conducted by—among others—all four members of the revived quadrilateral security cooperation framework, also called the “Diamond Alliance” or “the Quad”. Most analysts point to the developments and increased presence of foreign vessels as a response to China’s conduct in the South China Sea, especially its reclamation activities and construction of seven fortified outposts in the Spratly Islands.

In modern history, gunboat diplomacy has served as a signaling tool exercised by great powers. The United States declared itself a maritime power with the Great White Fleet launched by Theodore Roosevelt in the early 20th century. Compared to China and other major powers, Vietnam has only a very small navy. But Vietnam, through its foreign relations with states outside of the region, has been able to enact a sort of reverse gunboat diplomacy, by bringing the ships of powerful allies to its shores as a deterrent against Chinese aggression. If Vietnam hopes to expand its naval diplomacy with foreign partners, the South China Sea presents a great opportunity for mutual interests to meet. Whether in international trade, geostrategy, or natural resources, the South China Sea presents itself as an invaluable crossroads. Geopolitically, it constitutes a bridge between the Indian and Pacific Oceans, and serves as a gate for Chinese warships seeking to expand westward. By encouraging Australia, India, Japan, and the United States to engage more proactively in the South China Sea and ensuring a regional welcome for the Quad, Vietnam protects its own interests and those of foreign powers with the vision of a “free and open Indo-Pacific”.

About Ngo Minh Tri

Ngo Minh Tri is a managing editor of the Thanh Niên News based in Ho Chi Minh City, Vietnam. He conducts research on international security affairs, with a focus on Asian security issues.